Few directors encapsulate the insidious toll of loneliness as well as Andrew Haigh. Haigh’s previous works, “Weekend” (2011), “45 Years” (2015) and “Lean on Pete” (2017), have all dabbled in isolation. His debut, “Weekend,” best mirrors his latest as a story of two men who come together, seeking refuge in the other through sex and companionship – but “All of Us Strangers” is the director’s sharpest visual depiction of loneliness. Haigh delivers a messy yet emotionally potent story about the ghosts we burden ourselves with, the ones who bind us to the past and the ghosts we inevitably make by loving anyone at all.

There’s a simplicity to the narrative that acts like a Trojan horse for Haigh’s cinematic peculiarities and penchant for visual grandiosity. We meet Andrew Scott’s protagonist, Adam, as he takes in the desolate London morning. We follow him through his daily monotony as he gets high, stares at an unwritten screenplay and putters around until a fire alarm goes off and he’s forced to go outside. He’s yet to speak a word, yet the direction and framing conveys everything we need to know about him, and he sits separate from the world. The fire alarm is our first clue something isn’t right. Despite the enormous apartment complex, he’s the only one who exits, seemingly the lone tenant, until he meets eyes for the first time with Harry (Paul Mescal), who stands from his own apartment building looking down on him. Later, Harry appears on Adam’s doorstep, drunk, asking to come in before being turned away.

But it’s not just that they’re the only two souls living in the near-abandoned apartment complex that makes Adam’s world feel askew. We learn that Adam lost his parents (Jamie Bell and Claire Foy) in an accident when he was 11. This makes the moment he reunites with them at his old family home, seeming alive and well, all the more beguiling. As he talks with them around the dinner table the film’s tone moves from unsettled to hypnotic in its eerie warmth. Who wouldn’t, shown a past they believed to be gone, be happy to take moments of familial comfort? Adam hardly questions them appearing as young as the night they died, with Adam now older than both. As Adam continues to visit, he finds ways to reconcile who he knew as a child with the parents who are trying to know him as an adult. Through conversations about his sexuality, their mistakes and how they always believed they’d have more time to “get better at it,” there’s healing, even as the chasm between Adam and the natural world widens.

The two stories don’t marry as well as they could, despite a turn that leaves a devastating emotional bruise. As much as we enjoy the back and forth between Adam and his parents, with Foy and Bell delivering brilliant, restrained performances, Adam and a burgeoning relationship with Harry are just as captivating and linked in spirit and tone. As Adam and Harry burrow into the confines of Adam’s apartment, they might as well be the only two people on the planet. This is of course by design of Haigh and cinematographer Jamie D. Ramsay, who infuses scenes with disconcerting lighting and framing.

Adam and Harry drape over one another in bed with the edges of the frame consumed in darkness – suggesting that if they were to fall off, they’d be falling into an abyss. What’s romantic suddenly grows foreboding. A predictability of where their story will go doesn’t lessen the impact once the emotional fallout occurs.

The deeply felt performances ground the story, especially in the moments of hallucinogenic free fall as Adam loses his grip on time and reality. Scott brims with wounding emotional intensity as a man who has so long been used to being on his own that the warmth and vulnerability shown to him by others has him fumbling to respond. He has to physically shake himself to get words out in tense moments; at other times his mouth moves uninhibitedly. As Harry, Mescal stuns, playing an active supporting role to Scott’s Adam with enough light and magnetism to draw our eyes and undercut a striking sadness.

There’s so much texture to the film that it becomes overwhelmed in spinning to wrap up loose threads. That’s what makes it so transfixing, as we get different versions of Adam depending on who he’s with. Based loosely on the 1987 novel “Strangers” by Taichung Yamada, the story haunts not just because of Adam’s parents but because of it suggestions of how many versions of us there are. Adam and Harry are often depicted in the apartment’s elevator, which spins multiple, endless images of them in its reflection. It is heavy-handed, but speaks volumes and digs deep into the ways in which we busy ourselves not to face all the what-ifs in life.

“All of Us Strangers” is never bittersweet despite aching for companionship and grappling with specters from the past and what they mean. Are they a comfort, a burden, a chance for reconciliation only when they’re gone? Haigh’s film refuses to give easy answers, with scenes that carry the sensation of bone-deep fatigue that comes when facing the world becomes too much. Ending on a note of deliberate ambiguity, the film’s raw edges and open heart bleeds with empathy for its characters as they seek answers to who they are and those who surround them.

• At Landmark Kendall Square Cinema, 355 Binney St., Cambridge.

Allyson Johnson is editor-in-chief of the entertainment website InBetweenDrafts.